By Dr. Hans H. Stein

April, 2011

There are a number of high fiber ingredients available to swine producers. High-fiber ingredients are often available at relatively low costs because these ingredients cannot be used in the biofuel industry. High-fiber ingredients are, therefore, often attractive in feed formulation to reduce diet costs.

Many high-fiber ingredients are available

The most common high fiber ingredients that are available include wheat middlings, corn germ, corn germ meal, corn gluten feed, soy hulls, and alfalfa meal (Table 1). All of these ingredients are primarily used as energy sources in the diets and will, therefore, mostly replace corn in the diets. Oilseed meals such as canola meal, cotton seed meal, and sunflower meal are primarily used as sources of amino acids and will, therefore, substitute soybean meal in the diets, but they all contain more fiber than soybean meal and will increase the fiber concentration in the diets. Distillers dried grains with solubles (DDGS) and corn germ are unusual ingredients because they contains high levels of fiber as well as high levels of fat.

Characteristics of high-fiber ingredients

In contrast to fat, starch and protein, pigs do not digest fiber in the small intestine. However, microbes that reside primarily in the large intestine may ferment some of the fiber in feed ingredients, which results in production of volatile fatty acids that are absorbed by the pig. However, the proportion of the fiber that is fermented is usually relatively low and the energetic value of the volatile fatty acids that are absorbed is less than that of other absorbed nutrients. High fiber ingredients, therefore, usually contribute less energy to the pig than low-fiber ingredients and the energy concentration of the diets is often reduced if high fiber ingredients are used. The exception to this rule is for ingredients such as DDGS, HP-DDG, and corn germ that all contain high amounts of fat or protein in addition to the high concentrations of fiber.

Performance of pigs fed high-fiber diets

Gestating sows tolerate relatively high amounts of fiber and diets fed to gestating sows may contain higher levels of fiber than diets fed to lactating sows and growing pigs. Growing pigs often perform better on low-fiber diets than on high-fiber diets, but many high-fiber ingredients can be included in diets for weanling and growing-finishing pigs without negatively affecting pig performance. It is, therefore, possible to include up to 30% of many high fiber ingredients such as wheat middlings, corn germ, or DDGS without negatively influencing pig performance. Other high-fiber ingredients such as corn germ meal, corn gluten feed, and alfalfa meal, however, is usually included at less than 20% in diets fed to most categories of pigs.

Table 1. Commonly used high fiber ingredients in diets fed to swine

¹The listed inclusion rates are based on best estimates by the author. Not all ingredients have been tested in titration experiments with practical diets. The listed inclusion rates assume that the ingredients are included in corn-soybean meal based diets. If several high-fiber ingredients are included in the same diet, inclusion rates may need to be reduced.